Cable anchor for well derrick lines



May 15,1951 c. R. ATHY ET AL Y -CABLE ANCHOR FOR WELL DERRICK LINES Filed oct. 29, 1947 Patented May 15, 1951 CABLE ANCHOR FOR WELL" DERRICK LINES Clifford R. Athy, Dallas, Tex., and rCharles R.

Konkle, Columbus, Ohio, assignors to International Derrick & Equipment Company, Columbus, Ohio, a corporation of Ohio Application October 29, 1947, Serial No. 782,852

1 Claim.

This invention relates to cable anchors and particularly to an improvement in the type of anchor employing a cable-snubbing drum,

This type of cable anchor is known in the oilfields as a deadline anchor since it is usually employed in retaining the deadline of the block and tackle on the drill hoist. The cable, in such an application, leads down from the fixed block of the derrick to the drum and, after two or three turns about the drum, is securely clamped. The tension in the cable is gradually reduced throughout the turns, due to the contact with the stationary drum surface, so that only a comparatively small amount is present at the clamp. Thus, when the load is removed from the cable and suddenly reapplied, the sudden increase is absorbed by the drum and an injurious effect on the cable at the rigid clamp is prevented.

A new source of injury, however, is introduced by the drum in that the slackening of the cable allows the turns to relax and expand. When tension is subsequently applied, the turns must readjust themselves by sliding and crowding upon the drum and each other and are frequently abraded in the process. The danger is also present that one turn will move over atop an adjacent one and will suddenly slide off, under load, with a consequent injurious jolt to the entire system.

Attempts have been made to limit the radial movement of the slackened cable on the drum but, to our knowledge, have not been completely successful in solving the problem. We, on the other hand, have formed a very satisfactory solution in actually limiting the amount of cable which can return to the drum when tension is relaxed. The limiting effect need, therefore, be applied at only one place, namely, where the high-tension part of the cable leaves the drum, instead of on the turns themselves.

A difculty is encountered in placing an anchor of the present type in service and in subsequent adjustment because of the rather great resistance of the cable to bending and to laying in smooth turns. We have found that a very satisfactory degree of control may be gained by providing a cable guide at the proper point of entry of the high-tension part of the cable to the drum. This, in conjunction with the clamp at the low tension side, defines the cable direction and facilitates the proper positioning of the turns.

Another object, therefore, is to facilitate cable control by provision of a guide for the hightension part of the cable.

Still another object is to provide a cable anchor of the present type in a very simple form which is adapted to bel secured against an existing structure, such as the derrick itself, andv which, therefore, needs no base rstructure of its` OWII.

parent by the following specification and claim and by the appended drawings. g

In the drawings, Y

Fig. 1 is an end elevational view of the cable.

anchor of this invention supported on a structural column;

Fig. 2 is a side elevational view of the same and Figs. 3, 4, and 5 are cross-sectional views taken on the correspondingly numbered planes in Fig. 2.

In the drawings, in which a preferred embodiment of our invention is illustrated, it will be seen that a very simple and economical structure is obtained by the use of two flat plates and an interposed band. The base plate I0 is extended, at top and bottom, to provide space for mounting bolts II, by means of which the device may be secured to a structural element, such as the column I2, of the rig. Mounting bolts II which ocour at the drum location are of appropriate length to extend therethrough.

The snubbing drum, itself, is formed of a band I3 welded or otherwise secured against the plate I0. The outer or retaining plate I4 is welded or otherwise secured to the outer edge of the band. Both plates extend beyond the band periphery to furnish drum rims.

A cable guide I5, best seen in Figs. 2 and 5, is carried by an extension I6 of the otherwise circular plate I 4. The guide comprises a split block, half of which is carried by-the extension I6, as shown at I'I, and the other half of which provides a removable cap I8 with retaining bolts I9. A channel 20 for the cable C is formed in the halves and is preferably flared as indicated at 2|.

A cable clamp 22 is mounted on an extension 23 of the base plate. Two replaceable shoes 24 are adapted to clamp the cable, one being loosely retained on the base plate by a stud 25 and confined byv stops 26 and the other being loosely carried in a removable cap 21. Clamping pressure is applied by means of bolts 28.

A separable clamp 3l) is formed of similar halves and may be secured at any desired point on the cable by means of bolts 3|. The purpose of tiis clamp is to provide an abutment on the cable which will engage an abutment on the drum structure to prevent an undue amount of cable from uncoiling from the drum. The upper surface of the cable guide I5 very conveniently Other objects and advantages will be made ap- I furnishes the fixed abutment in the present embodiment.

In the operation of the device the cable leads downwardly, at C', as the deadline of a hoisting system and, after passing through the guide I5, is Wound about the drum for a few turns and then passes through the clamp 22.

spool as it'isdesirable to add increments of cable intermittently to the system to compensate4 The clamp 30 is so positioned'l on the cable that a small sepan;atign;exists;be@A

for -wear and tear.

tween it and the xed abutment when the cable is, under tension. A slight#-anfiouni?*offelema tion of the turns is thus all,"Qwediwhen;tiiegnalglefl 15,;

The part C" be- Y Y yond the iclampusnallytextendslto.latreserve cable` lmfixed to said cable at a position in which the is slack and a slight worliii'igw`is,.`ail'orded;tu.,v

prevent shock when the load is suddenly reapplied.

While we have illustrated and described specific forms of drum, guide, and clamps, itwill Vbe understooithat numerous Changes may, be. mafie instead-of "being entirely separate; may-be carjried. by. asprinearmrisins thedrum. structhrew.. may; otherwise be;myablymountedfon..

the'l'a'tter.'

We claim: Amable lanchor ccmprisingeabase, member stop is spaced from said guide when the portion of'saidf;cabieeairynggsaid stop is under tension and engagedwithsaid guide upon contraction of` the cable -whenjthe -tension thereon is released.

CLIFFORD R. AT1-IY. CHARLES R. KONKLE.

REFERENCES CITED Thagfollowing references are of record in the 20 le of this patent:

UNITED STATESS. PATENTS?L Number Name Date 1,218,138m Wachter Mar; 6; 191,7" 1,499,477 Reilly 'Y July4 1; 1l2flALY 11,884,037 Malone oct,- 25; 1932-5; 2,130,170 Wood`A sept; 13, 19,331 2-,-28 2\,6 85i Timbs May 12, 1942; 2,4243'760 Konkle` July 29,'19 17.5; 

